Apply constraints to elements in the model to establish and maintain relationships between them.
This video demonstrates the following:
Constraints in Revit allow you to lock elements and establish relationships. After you establish constraints, they will remain unchanged when the model is modified.
The Dimension tool was used to create a sequential, multi-segmented dimension for the grid lines. To establish an equality constraint from the dimension, click the Equality icon. The grid lines are now equally distributed across the building. When you resize the grid, the equality constraint is maintained.
Notice that the dimension for the stairwell is unlocked, so the dimension value is modifiable and the element that it references can move in any direction. Click the lock icon to create a constraint. Now when you drag the wall, the size of the stairwell does not change.
Alignment is another common constraint. For example, you want the stairwell on the left side of the building to line up with the stairwell on the right. The Align function includes the ability to lock the alignment between the two objects. Now when you change the position of one stairwell, the other stairwell remains aligned.
You can also remove constraints. When you delete the dimension for the grids, you are prompted to either delete the corresponding constraint or keep the constraint without the dimension.
Use dimensional constraints and alignments to create relationships between elements in a building model.